Self-training idler



Oct. 4, 1938. C.'SOLLENBERGER 2,132,052 Y SELF TRAINING IDLER Filed Dec. 16, 1935 2 Sheets-Sheet l (M i t Q 1 I {I a, N I w f" v Q I'm/awn- Q Zieue Clefiajoaeize ger Q *4 m hb wmv 7 W 1938- R. c. SOLLENBER'GER 2,132,052

SELF TRAINING IDLER Filed Dec. 16, 1935 2 Sheets-Shet 2 Patented Oct. 4, 1938 UNITE STATES ATENT OFFKIE SELF-TRAININ G IDLEE Application December 16, 1935, Serial No. 54,619

' 20 Claims.

This invention relates to belt conveyors, and more particularly to training idlers.

A training idler, as the name implies, will function to train the conveyor belt traveling thereon, so as to maintain the belt in a centered position on the idler, thereby counteracting tendencies of the belt to deviate from a straight line course. In a long belt conveyor, it is desirable to support the belt at one or more points along its length by a training idler or idlers, to keep the belt from running out of line.

Objects of the present invention are to obtain improvement in the functioning of training idlers, and improvements of practical advantage with respect to construction.

The invention will be hereinafter described with reference to an illustrative embodiment thereof, shown in the accompanying drawings, and will be more particularly pointed out and defined in the claims following the description.

In the drawings:

Fig. 1 is a top plan view of a training idler of one practicable type and construction containing an embodiment of the invention; a portion of the conveyor belt which travels on the idler being represented in this figure by dotted lines.

Fig. 2 is a sectional View of a portion of the idler, showing the manner of mounting the idler rolls.

Fig; 3 is a top plan view of the right-hand half of the idler, indicating in dotted lines a displaced position of the right-hand training roll of the idler. 1

Fig. 4 is a front elevation of the half of the 33 structure shown in the preceding figure.

Fig. 5 is an end elevation, also indicating by dotted lines a displaced position of the right-hand training roll.

In the drawings, 1 denotes a conveyor belt,

M traveling in the direction indicated by the arrow in Fig. 1.

As shown, the conveyor belt is supported on an idler comprising a number of conveyor rolls, in this instance three rolls 2, 3, 4,, arranged trans- 43 versely of the belt in end to end relation, the intermediate roll 3 being horizontal and the two end rolls 2 and 4 being oppositely inclined. This is one example of the familiar type of conveyor idler which comprises a plurality of conveyor rolls arranged end to end on relatively inclined axes to provide a trough-shaped support for the conveyor belt.

Freely rotating on frictionless bearings, the

I conveyor rolls support the traveling belt without exerting a frictional drag. In Fig. 2 the rolls are shown equipped with sealed and grease-packed bearing units of the type comprising concentric race -rings and interposed balls, the outer racerings 5 of these units being fitted and secured in properly centered hub sockets in the ends of the rolls. The inner race members of these bearing units are shown constructed as socket members 6 which receive and are supported on ballshaped ends I of stub shafts carried by the roll supporting standards. Double-headed stub shafts 8 clamped in the upper ends of the intermediate supporting standards 9 carry the roll bearings in adjacent ends of adjacent rolls, and single-headed stub shafts In clamped in the upper ends of the end standards H carry the roll bearings in the outer ends of the end. rolls 2 and 4. The ball-shaped ends or heads of thesestub shafts are adapted to-be inserted through and withdrawn from the supporting standards, thus permitting ready assembly and disassembly of the parts. The construction here alluded to with reference to the roll bearings and stub shaft mountings therefor exemplifies one practicable manner for the mounting of the roll bearings, the

same being of a special advantage in connection with other features of the idler structure herein to be described.

The conveyor rolls are mounted in a manner permitting either of the two end rolls 2 and 4, hereinafter referred to as training rolls, to be skewed or canted for training the belt, and means are provided whereby the lateral shifting of the belt to either side from a centered position will cause the canting of the training roll at that side, as suggested by the dotted line showing in Figs. 3 and 5, with-the effect of training the belt back to centered position, whereupon the canted roll will resume its normal position at right angles to the direction of travel of the belt. The construction embodied in the illustrative idler for mounting the conveyor rolls and accomplishing the training action as above indicated, will now be described.

Pivotally supported at their inner ends on fixed supports, and at their outer ends on movable supports, the training rolls 2 and 4 are capable of being rocked or swung'on their inner end supports in parallelism or approximate parallelism with the inclined side portionsof the conveyor belt riding on said training rolls. The fixed supports referred to are typified by the intermediate roll supporting standards 9, carried by a stationary supporting structure represented in the drawings by the angle bar l2 which may be a fixed part of the supporting frame-work for the belt conveyor. Movable supports for the outer ends of ing the end supporting standards I I on base members l4 affixed to the angle bar l2. Said angle bar l2, carrying the fixed intermediate roll supporting standards 9 and pivotally mounted end standards H, typifies a stationary stand in which the conveyor rolls are mounted. The pivot pins or trunnions l3 of the pivotally mounted end standards H are shown horizontally disposedat right angles to the direction of travel of the belt,

so that these standards can rock or tilt in a manner to'move the outer ends of the training rolls in approximate parallelism with the direction of travel of the belt, or so as to swing said rolls as above-described. In this swinging movement, the training rolls must not only pivot on their fixed supports at their inner ends, but must also have axial and universal play with respect to the movable supports carrying their outer ends. This action is allowed by the use of the type of bearing units and mountings therefor previously referred to. The ball-headed ends 7 of the stub shafts carried by the supporting standards fit rotatably and slidably in the socket members 6 constituting the inner members of the bearing units. With the use of these bearing units and stub shaft mountings, it will be apparent that the training rolls can rock properly on their inner end supports, and that the roll bearings in the outer ends of said training rolls will move with the necessary rotational and slip' motions on the stub shafts ID of the movable outer end supports. Within the broader aspects of the invention, other suitable mounting constructions may be employed for the same general purpose. For example, the training rolls could be mounted on axles extending therethrough and ball-seated on fixed supports at their inner ends and slidably ball-seated on movable supports at their outer ends. But the illustrative construction, wherein the roll bearing units include socket members engaging ball-shaped ends of short stub shafts fixed in the'supporting standards, is admirably adapted for the purpose and of special advantage, making a simpler and more practicable construction than would be required if the roll bearings were carried on axles extending through the rolls.

The pivotally mounted end standards I I should be held in normal position in such manner as to require a substantial effort to tilt them, in order to prevent any accidental displacement of the training rolls from their normal positions at right angles to the direction of travel of the belt, and the standards should return to normal position as soon as relieved from the displacing effort. In the illustrative apparatus, the standards H are normally erect, so that they carry the roll-supporting stub shafts ll! directly over the pivot pins l3. Movement of the standards from normal position in a direction contrary to the direction of travel of the belt is prevented by motion limiting stops l engaged by abutments IS on the standards. These motion limiting stops l5 are pointed or ridged so as to prevent any obstructing of their functioning by accumulation of dirt or trash. For yieldingly urging the standards to and holding them in normal position, either a counterbalancing Weight means or spring means, or both, could be employed. In the construction shown, the standards are held in normal position by the Weight of thehereinafter mentioned shifter rollers 23 and by spring means. As best shown in Fig. 5,

the spring means associated with each standard I i is represented by a compression spring I? reit would be on the opposite side of the standard,

and the right-hand side thereof would be designed to limit the tilting motion, which in the illustrated construction is limited by the compression action of the spring.

Since the several conveyor rolls including the training rolls 2 and 4 are freely rotatable on frictionless bearings, the veering of the conveyor belt from centered position on the idler would not in itself exert such a frictional drag effect as to cant the proper roll for training the belt, in view of the resistance to displacement of the training rolls which is imposed by the means for yieldingly holding the end rocker standards H in their normal positions. Other means are therefore provided in the illustrative apparatus for causing the canting of the proper training roll as required to train the conveyor belt to centered position when it veers therefrom. For this purpose, shifting devices to be actuated by the belt are associated with the respective rocker standards H to rock them backwardly or in'the direction of travel of the belt. These shifting devices include guide rollers 23 arranged adjacent to the edges of the belt, said rollers being carried by the rocker standards H preferably on the forward side thereof so as to utilize the Weight of the guide rollers and their carrying arms to assist in holding the rocker standards in normal position. Assuming the conveyor belt to be properly centered on the idler, there would ordinarily be a clearance of say an eighth or a quarter of an inch between each edge of the belt and the adjacent guide roller, and only when the belt veers from centered position will either of these guide rollers be engaged. To avoid undue wear on the belt edges, the guide rollers 23- are preferably disposed at right angles to thesurfaces of the respective side portions of the belt. These guide rollers, which may be otherwise re ferred to as shifter rollers, are of the friction bearing type, so that a certain resistance is imposed to their rotation. Hence when an edge of the conveyor belt running out of line engages either of these guide rollers, the pressure resulting from such resistance to rotation will be transmitted to the rocker standard carrying such guide roller, causing the rocking of said standard in the direction of travel of the belt to an extent in proportion to the thrust exerted. Such rock-.

ing of the standard ll correspondingly shifts the outer end of the training roll with which it is associated, canting the training roll as indicated in dotted lines in Figs. 3 and 5, thus training the belt back to centered position on the idler,.where upon thetraining roll resumes normal position.- The canted position of the right-hand training roll indicated by dotted lines in Figs. 3 and '5 is rather exaggerated for convenience of illustration. In actualpractice the propertraining of the conveyor belt may be accomplished by slight deflections in the positions of the training rolls. Means for adjusting the positions of the guide rollers 23 and for adjusting the frictional drag exerted by these rollers are provided as follows. Each guide roller is carried from the rocker standard II with which it is associated by a bracket arm 24'bolted to the lug 25 on said standard by the bolt 26 parallel with the axis of the guide roller. Upon loosening the bolt.26, the arm 24 can be swung to adjust the position of the guide roller, according to the clearance desired between the guide roller and the edge of the conveyor belt. The guide roller is journalled on the shaft 21 rigidly secured to its carrying arm 24. The upper end of said shaft extends above the top of the guide roller and is screw threaded and has an adjusting nut 28 thereon, a washer 29 being interposed between said nut and the upper end of the guide roller. The adjusting nut can be screwed down to give any desired amount of drag tothe guide roller when it is contacted by the edge of the belt. Thus the guide roller is a friction bearing roller with anadjustable friction bearing, the nut 28 and washer below it serving for adjusting the friction. So if the guide roller should turn too freely, the nut 28 may be tightened to increase the drag of the roller on the belt when contact with the belt occurs, and thus increase the rocking. movement imparted to the standard H against the resistance of its spring.

From the foregoing, it will be apparent that the training idler herein shown and described is of highly practicable and efficient character. The mode of operation is such that its training action does not depend upon the exertion of a frictional drag on the conveyor belt by the training rolls, nor upon a skewing of the idler as a whole. All of the conveyor rolls of the idler may be freely rotatable on frictionless bearings, avoiding drag and undue wear on the undersurface of the belt at all times, and obviating resistance to the normal travel of the belt when running true. Only when the belt veers from a centered position does an. edge thereof contact with one of the guide rollers 23, which then imposes a sufiicient drag to cause the shifting in the direction of travel of the belt of the outer end of the training roll with which such guide roller is associated, with the effect of gently training the belt back to centered position, the training roll resuming its normal position as the training takes place or as soon as the training is effected. In the prior art there was used a training idler which depended upon employment of friction bearings in the training rolls, and upon a turning of the idler as a whole about a central vertical axis to accomplish the training action. Not only was such prior device subject to the objection that it constantly imposed a frictional drag on the belt, but also its training action was liable to be too violent. As the conveyor belt would shift laterally from centered position, the drag imposed by the training roll at the side toward which the belt shifted would be increased, and when this increase was sufficient to overcome the inertia of the idler it would pivot on its center bearing, one end of the idler being pulled forward and the other end moving backward. Thus the training action was doubled, and the belt was liable to be jerked from one off-center position to the opposite off-center position, whereupon the training action would be repeated in the reverse manner, and a condition might be set up whereby the belt would fluctuate from side to side. It was found necessary to impose arbitrary motion limits on such prior devices to obtain satisfactory results. As compared with such prior devices, the training action of the idler herein described is much superion Another objection to the prior device was that it required a special supporting framework, whereas the idler herein described does not require special framing for its support, and can be installed at any point in the conveyor line in the same manner as an ordinary supporting idler. As the prior idler depended for training action upon pivoting of the stand in which the conveyor rolls were mounted, it might fail to function properly if the stand should become clogged by material falling from the conveyor belt, whereas in the illustrative apparatus the conveyor rolls are mounted in a fixed stand and interference with the proper functioning is not likely to occur.

Obviously the illustrative apparatus may be variously modified as to details of construction and arrangement to suit various different conditions and requirements. Moreover it is not indispensable that all of the features of the invention be used conjointly since various features may be used to advantage in various different combinations and subcombinations.

What I claim as my invention, and desire to secure by Letters Patent, is:

1. A training idler comprising conveyor rolls arranged end to end on relatively inclined axes to provide a troughing support for a conveyor belt, fixed means for supporting the roll ends other than at the idler extremities, movably mounted means supporting the roll ends at the idler extremities, means yieldingly maintaining the rolls in normal relationship, and means whereby the shifting from centered position of the conveyor belt traveling on the idler will cause a roll displacement to train the belt back to centered position.

2. A training idler comprising conveyor rolls arranged end to end on relatively inclined axes to provide a troughing support for a conveyor belt, fixed means for supporting the roll ends other than at the idler extremities, movably mounted means supporting the roll ends at the idler extremities, said movably mounted means being yieldingly urged to position to maintain the last mentioned roll ends in normal position, and means controlled by the conveyor belt for causing displacements of said last mentioned roll ends as required to train the belt to centered position on the idler.

3. A training idler comprising conveyor rolls arranged end to end, including intermediate and end rolls, said end rolls being arranged on oppositely inclined axes, each of said inclined end rolls being independently movably mounted and adapted to be individually skewed for training a conveyor belt traveling on the idler, and means whereby the shifting of the traveling belt from centered position will cause the inclined end roll up which the belt rides to be skewed to train the belt back to centered position, said means comprising a pair of independently operable roll skewing devices, one operable by the belt when shifted laterally to the right for independently skewing the right hand end roll, and the other operable by the belt when shifted laterally to the left for independently skewing the left hand end roll.

4. A training idler comprising conveyor rolls arranged end toend, including intermediate and end rolls, said end rolls being arranged on oppo- Ii sitely inclined axes, fixed roll supports each arranged between and supporting the adjacent ends of a pair of rolls, movably mounted supports forthe outer ends of the end rolls movable for shifting said outer ends in a manner to swing said rolls on their inner end supports in parallelism or approximate parallelism with the inclined side portions of a conveyor belt traveling on the idler, the end rolls being suitably mounted on their supports to permit such action, means engageable by the traveling belt for moving said movable supports to cause displacement in the direction of travel of the belt of the inclined end roll up which the belt rides when it shifts laterally from a centered position, and means resisting such displacement and causing resumption of normal position of the displaced roll when sufficiently relieved of the displacing effort. l

5. A training idler comprising conveyor rolls arranged end to end, including intermediate and end rolls, said end rolls being oppositely inclined to support inclined side portions of a conveyor belt traveling on the idler, fixed intermediate sup-ports each arranged between and supporting the adjacent ends of a pair of rolls, supports for the outer ends of the end rolls movable for shifting said outer ends to swing said rolls on their inner end supports substantially parallel with the inclined side portions of the belt, stub shafts having ball-shaped ends carried by the respective supports, and antifriction bearing units in the roll endshaving socket members on which the inner race rings of the bearings are provided,said socket members fitted on said ball-shaped ends of said stub shafts, whereby the end rolls can pivot on their respective supports and move axially relative to their outer end supports when the latter'are moved.

6. In a training idler, a movably mounted training roll adapted to be skewed, supports,

therefor including a support movable 'to shift one end 'of the roll relative to the other, ballshaped ended stub shafts carriedby said supports, and roll bearings having socket members universally movably mounted on the ball-shaped ends of said stub shafts, the socket member of the roll bearing adjacent to the movable support being also slidable on the ball-shaped end of the stub shaft carried by said movable support.

7. A training idler having independently movably mounted training rolls adapted to be individually skewed and means operable by the belt traveling on said idler whereby the shifting of the belt from centered position will cause the independent skewing of the training roll at the side of the center to which the belt shifts, said training rolls being yieldingly urged to normal position, and said belt-operating means independently skewing each roll in a manner to center the belt.

8, A training idler having independently movably mounted training rolls adapted to be individually skewed for centering the belt, said rolls being freely rotatable on frictionless bearings, and means controlled by the belt traveling on said idler to cause the independent skewing of the training roll at the side to which the belt shifts.

9. In a training idler, a training roll positioned to support an edge portion of a conveyor belt and having its axis inclined to the horizontal, stationary means for axially supporting the lower end of said-roll, movably mounted means for axially supportingthe upper end of said roll normally maintaining it at right angles to the path of the beltbut movable for shifting said upper end in the direction of travel of the belt, and

means contactable by a belt edge running abhor:

mally high on said roll for so moving said last tioned to support an edge portion of a conveyor belt, stationary means for axially supporting the inner end of said roll, means for axially supportingthe outer end of said roll movable to shift said outer end in the direction of travel of the belt, said last named means comprising an unstably mounted tilting support, means for yieldingly holding the same in normal position, and means contactable by the belt for tilting said support.

11. In a training idler, a conveyor roll for supporting an edge portion of a conveyor belt, said roll mounted to permit skewing the roll for training the belt, a substantial eifort being required for the skewing, means contactable by the belt for exerting such effort, and means for adjusting the effort exerted by contact of the belt with said first named means. 12. A self-training idler having training rolls arranged for supporting a traveling belt at opposite sides of its longitudinal center, said rolls being independently movably mounted to permit them to 'be individually skewed, and a pair of independently operable means for independently skewing said training rolls, one of said means operable by the traveling belt when shifted from centered position to the right for skewing the right hand roll to train the belt to centered position, and the other of said'means operable by the traveling belt when shifted from centered position to the left for skewing the left hand roll to train the belt to centered position, each roll automatically resuming itsnormal positionmentioned standards being movable transverselyof the vertical plane of the roll axes, said rolls being mounted in their respective standards in a manner permitting them to be swung on their inner end supports in parallelism or approximate parallelism with the portions of the belt traveling on said rolls, and mechanism operable by the traveling belt for moving said movable standards to effect roll skewing operations to center the belt, the organization including means whereby the rolls resume a normal position pursuant to the centering of the'belt.

14. A self-training idler having training rolls for supporting a traveling belt at opposite sides of its longitudinal center, a stationary base, standards in fixed position on said base supporting the inner ends of said rolls, standards independently movably mounted on said base supporting the outer ends of said rolls, said last mentioned standards being movabletransversely of the vertical plane of the roll axes, said rolls being mounted in their respective standards in a manner permitting them to be swung on their inner end supports in parallelism or approximate parallelism with the portions of the belt travel-.

ing on said rolls, means yieldingly holding said movable standards in normal position, and means associated with each movable standard and operable by the traveling belt when it shifts from centered position toward said standard for moving said standard to skew the corresponding roll for training the belt to centered position.

15. A self-training idler having training rolls for supporting a traveling belt at opposite sides of its longitudinal center, a stationary base, standards in fixed position on said base supporting the inner ends of said rolls, standards independently movably mounted on said base supporting the outer ends of said rolls, said last mentioned standards being movable transversely of the vertical plane of the roll axes, said 'rolls being mounted in their respective standards in a manner permitting them to be swung on their inner end supports in parallelism or approximate parallelism with the portions of the belt traveling on said rolls, means yieldingly holding said movable standards in normal position, and belt-engageable devices carried by said movable standards whereby the traveling belt if it shifts laterally from centered position toward either of said standards will move it for skewing the corresponding roll to train the belt to centered position.

16. A self-training idler having training rolls for supporting a traveling belt at opposite sides of its longitudinal center, a stationary base, standards in fixed position on said base supporting the inner ends of said rolls, standards independently movably mounted on said base supporting the outer ends of said rolls, said last mentioned standards being movable transversely of the vertical plane of the roll axes, said rolls being mounted in their respective standards in a manner permitting them to be swung on their inner end supports in parallelism or approximate parallelism with the portions of the belt traveling on said rolls, belt-engageable means carried by said movable standards whereby the traveling belt if it shifts laterally from centered position toward either of said standards will move it for skewing the corresponding roll to train the belt to centered position, and means for automatically returning each roll to its normal position pursuant to the performance of its training function.

17. A self-training idler having training rolls for supporting a traveling belt at opposite sides of its longitudinal center, a stationarybase, standards in fixed position on said base supporting the inner ends of said rolls, standards independently movably mounted on said base supporting the outer ends of said rolls, said last mentioned standards being movable transversely of the vertical plane of the roll axes, said rolls being mounted in their respective standards in a manner permitting them to be swung on their inner end supports in parallelism or approximate parallelism with the portions of the belt traveling on said rolls, belt-engageable means for operating said movable standards whereby the traveling belt if it shifts laterally from centered position toward either of said standards will move it for skewing the corresponding roll to train the belt to centered position, and means for automatically returning each roll to its normal position pursuant to the performance of its training function.

18. A self-training idler having training rolls for supporting a traveling belt at opposite sides of its longitudinal center, tiltable supporting standards for the outer ends of said rolls, said standards being independently pivotally mounted below the roll axes for tilting movement transversely of said axes, the rolls being'supported by said standards and at their inner ends in a manner permitting the shifting of their outer ends by said standards, means operable by the belt for tilting the right-hand standard forwardly when the belt shifts from centered position to the right, means operable by the belt for tilting the left-hand standard forwardly when the belt shifts from centered position to the left, and means causing the standards to resume normal position pursuant to the centering of the belt.

19. A self-training idler having training rolls for supporting a traveling belt at opposite sides of its longitudinal center, tiltable supporting standards for the outer ends of said rolls, said standards being independently pivotally mounted below the roll axes for tilting movement transversely of said axes, the rolls being supported by said standards and at their inner ends in a manner permitting the shifting of their outer ends by said standards, means yieldingly holding the standards normally erect, means operable by the belt for tilting the right-hand standard forwardly when the belt shifts from centered position to the right, and means operable by the belt for shifting the left-hand standard forwardly when the belt shifts from centered position to the left.

20. A self-training idler comprising a roller support for a traveling belt, tiltable supporting standards for the ends of said roller support, said standards being pivotally mounted below said ends for tilting movement transversely of said roller support and being independently operable, means yieldingly holding the standards normally erect, and means operated by the belt when it shifts from centered position toward either end of said roller support for independently operating the standard at that end to tilt it forwardly.

REUEL CLEM SOLLENBERGER. 

